There was nothing small this year about Small Business Saturday sales.

Consumers spent $5.5 billion at independent retailers Saturday, according to a survey released Monday from the National Federation of Independent Businesses (NFIB).

Small Business Saturday, when consumers are encouraged to support their local small businesses two days after Thanksgiving, gets bigger every year, says Karen Mills, head of the Small Business Administration.

"We see tremendous momentum out there," says Mills. "This Small Business Saturday has really gone viral."

Small businesses can't usually compete with big-box stores' big sales on Black Friday, so many hope to use Small Business Saturday to get a piece of the action during the biggest shopping weekend of the year.

Small Business Saturday is the most important shopping day of the season for 36% of independent retailers, according to NFIB. Only 24% say that day is Black Friday.

Leah Daniels, owner of Hill's Kitchen, says this Small Business Saturday was probably twice as big as last year's, and the store was packed all day.

Ross Steinman, psychology professor at Widener University, says the popularity of Small Business Saturday is a revolt against big-box stores from consumers who are willing to pay extra and see the money go to their communities.

"There's so much negative attention in recent years on Black Friday and the rampant consumerism that's associated with it," he says. "Small Business Saturday is a response to that."

Laura Smith, 52, says she's a big fan of Small Business Saturday. She spent the day shopping at all her favorite stores in Terrytown, Va., and was sure to have lunch at Can Can, a locally owned French restaurant.

"It was really pleasant. It was fun and kind of like back in the old days where people would just walk up and down the street visiting the local stores," says Smith.

Jim Brownell, vice president of retail solutions for GT Nexus, says that Small Business Saturday is a great opportunity for retailers because there are "a lot of feet on the street," but it doesn't work unless they get the word out about promotions.

"It's unfortunately going to require some sort of service promotion or product promotion to draw people into the stores," Brownell says. "You can't sit back and hope that the SBA with all their advertising is really going to be the ones that will bring everybody in."

Alan Au, co-owner of Jimmy Au's For Men 5'8" and Under, a fancy clothing store for shorter men, had a big Small Business Saturday sale on pretty much everything, but didn't advertise the sale beyond individual invitations to customers.

"The more full the store is, the harder it is to help anybody," says Au. "I function a lot better with a steady stream of customers."

Nevertheless, the store was busy the whole day, and Au says it's a good indication December sales will be up as well.

When Au's store was in the Glendale, Calif., shopping mall, his Black Friday sales drew customers who were already in the mall to make other purchases.

However, once the store moved to a street location in Beverly Hills, he found he was trying to compete with the big retailers at the mall, whose Black Friday crowds he previously relied on for customers.

"We tried to compete against that with some really killer deals, but we can't beat something like that," says Au. Now he holds the sale on Saturday.